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Full text of "Alaskan glacier studies of the National Geographic Society in the Yakutat Bay, Prince William Sound and lower Copper River regions"

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General Description. From snow-covered Mount St. Elias and Mount Logan, 18,000 and 19,500 feet high, and from the 10,000 to 16,000 foot mountains to the east and west a multitude of glaciers descend, the six largest of which named from west to east, are the Guyot, Tyndall, Agassiz, Seward, Marvine, and Hayden. These glaciers, fed by many tributaries, have their sources far back among the mountains and their upper portions are unknown.
Where they emerge from their mountain valleys they are broad ice streams, ranking among the largest of the Alaskan valley glaciers. The great volume of ice which flows out of these valleys suffices to build the broad ice plateau (PI. VH) which skirts the mountain base from Yakutat Bay to Robinson Hills, which, according to Russell, has an area of about 1500 square miles, more than the area of the state of Rhode Island, and far the largest glacier in America, or, for that matter, in all the world, excepting only in the polar regions.
The single glaciers lose their individuality at the mountain base, where they all coalesce to form the continuous ice plateau; but they nevertheless maintain an appreciable influence on the Malaspina Glacier even to its outer margin. Because of tTiig influence the ice plateau really consists of more or less pronounced lobes with boundaries sometimes marked by medial moraines, and with a moderately lobate front. Tyndall and Guyot Glaciers, deflected by the Chaix Hills, a south-extending spur of Mt. St. Elias, appear to unite to form a pronounced lobe on the western margin, where the ice formerly crowded out into the sea and was terminated by a magnificent clifl from which icebergs were discharged into the open Pacific. From all the photographs and descriptions which we have been able to obtain from publications of explorers and from conversation with prospectors this western, or Guyot, lobe of the Malaspina differs from the eastern portion of the glacier in maintaining a generally crevassed condition from the mountain base to the sea. It is said to present an insurmountable barrier to travel, and it is the common belief of prospectors in this region, that the Malaspina Glacier is absolutely inaccessible from the west. It is certain that no one has yet crossed it. The Tyndall Glacier was easily traversed by the Schwatka and Topham parties in 1886 and 1888 but no attempt was made to cross the Guyot.
The Agassiz lobe, next east of the Guyot, fed by Libbey and Agassiz Glaciers, is a well defined lobe, bordered by moraines on both the eastern and western margins, and faced by a broad tract of stagnant and semi-stagnant ice bearing an extensive waste of ablation moraine, and on its outer edge supporting a forest of spruce and cottonwood. Around the periphery of this lobe there is the greatest development of ablation moraine, and